US winter storm toll mounts to 50

Harsh winter weather has dogged much of the US, leaving scores of people dead and thousands without power.

Harsh winter weather has dogged much of the United States, leaving scores of people dead, hundreds of thousands without electricity and jeopardising California's citrus crops.

More than 50 deaths across nine states were blamed on the storm, the majority in car accidents on icy roads, US media reported. Several were killed by carbon monoxide poisoning from malfunctioning generators and heaters after the power went out.

A massive storm that began churning across the country on Friday brought ice, sleet, rain, flash floods and even a few tornadoes as it moved from the southwestern states of New Mexico and Texas to far northeastern Maine.

A winter storm warning was in effect on Wednesday in parts of North and South Carolina, and a winter storm watch across New Mexico, Texas, Oklahoma and northeastern Maine, the National Weather Service said.

An icy snap in normally balmy California led Governor Arnold Schwarzenegger to warn that the region's citrus fruit industry could be devastated, with damage "close to a billion dollars."

California supplies nearly a quarter of citrus fruit sold in the United States, according to state agricultural authorities.

Snow forced the closure of a 60-kilometer stretch of one of California's biggest transport routes north of Los Angeles on Wednesday, transport authorities said.